In spin balancing control systems, such as washing machines or other rotating systems or rotating devices, problems are generally associated with injector valve actuation timing variation. Timing variation, in particular, often presents problems. The timing variation is the difference between the intended injection event as dictated by a controller and the actual injection event that occurs in the rotating system or rotating device. In such rotating systems or rotating devices, a rotating member has a certain xe2x80x9cout of balance,xe2x80x9d which can be represented by a vector with phase and magnitude. Such a balance control system or rotating system typically utilizes liquid injector valves to place mass, such as fluid, on the rotating member at certain angles to compensate for the xe2x80x9cout of balancexe2x80x9d. The injectors are generally stationary and project mass or fluid across an air gap to discrete channels on the rotating member that, in turn, directs the mass or fluid to specific angular locations on the rotating member.
Injection timing can be critical to the operation of the rotating system or rotating device because inconsistent actuation of the injector valves may result in the placement of mass or fluid at the wrong location. As rotational speeds increase, the injector valve timing becomes even more critical because a fixed timing error in the injector valve actuation may result in an increased error for angular placement. Ultimately this can result in an unstable or slowly converging control system. Some of the causes of inconsistent injector valve actuation include physical production variation from one valve to the next and the aging of the valve through its lifetime of operations.
Compensation for injector valve variation can be achieved by placing a sensor in an air gap between the stationary valve and rotating member. Typically, however, there is little room to place a sensing element in the air gap. The present inventors have thus come to realize that what is needed to solve the aforementioned problems is a method and system for determining when actual fluid is injected into the rotating system so that little doubt exists where the counter balance has been applied.
The following summary of the invention is provided to facilitate an understanding of some of the innovative features unique to the present invention and is not intended to be a full description. A full appreciation of the various aspects of the invention can be gained by taking the entire specification, claims, drawings, and abstract as a whole.
In accordance with addressing the shortcomings of the prior art, it is one aspect of the present invention to provide sensor methods and systems.
It is another aspect of the present invention to provide methods and system for detecting the transfer of mass in a rotating device or rotating system, such as, for example, a dishwasher, clothes washing machine, circuit board washing machine, etc.
It is yet another aspect of the present invention to provide methods and systems for detecting the transfer of fluid in a rotating device or rotating system.
It is still another aspect of the present invention to provide methods and system for detecting the transfer of fluid from stationary to rotatable members in rotating devices or rotating systems.
It is also an aspect of the present invention to provide methods and systems for detecting the transfer of fluid in a rotating device or rotating system utilizing closed-loop feedback techniques.
In accordance with various aspects of the present invention, methods and systems are disclosed herein for detecting mass transfer in a rotating device or rotating system. Mass may be transferred from the stationary member to the rotating member. The transfer of the mass from the stationary member to the rotating member may be detected utilizing a sensor. Such a sensor may be configured as a stand-alone device that a user installs on a washing machine. A controller linked to the stationary member thereafter may receive a signal that the transfer of mass has been detected, in response to detecting the transfer of mass, thereby permitting the controller to compensate future mass placements in the rotating system according to measured latencies. The mass may comprise a fluid. The fluid itself may be conductive.
A gap is generally configured between the stationary member and the rotating member. One or more wires connected to the sensor may be inserted into a stream of such fluid that is created when injectors are activated. Two wires may preferably be utilized, but additionally wires can be implemented within the gap if necessary. An electrical circuit thus may be completed when the stream of fluid travels through the gap and comes into contact with the wires connected to the sensor and sensor circuitry associated with the sensor. The conductive fluid may have a particular level of conductivity. The level of conductivity is preferably greater than the level of conductivity associated with open air. The sensor may be configured as a capacitive sensor, a contact-type conductivity sensor, a non-contact type conductivity sensor, or an optical sensor.